Kerberos, which ships with most operating systems, is a suite of
authentication protocols that can enable features such as single
sign-on, where a single login and password can be used to access
multiple websites or applications. It was developed as part of MIT’s
Project Athena in the 1980s.

While Microsoft has implemented Kerberos protocols in its Windows
2000, XP, Server 2003 and 2008 and Vista operating systems, the vendor
was accused eight years ago of subverting the standard by adding
proprietary extensions.

During Microsoft"s US anti-trust trial, an MIT professor testified
the vendor had extended the Kerberos specification used by its Windows
2000 OS such that a non-Microsoft server could not use the security
features of the PC"s OS.

That evidence contributed to the view that Microsoft gave lip
service to the importance of interoperability, but implemented
technical blocks that locked out competitors. Microsoft eventually
released details on its modifications to Kerberos.

After both US and European anti-trust trials, Microsoft forcibly and
voluntarily took steps to improve its documentation of protocols as
well as open up more of its internal technical details.

Microsoft"s participation in the Kerberos Consortium "shows
Microsoft"s continued and growing desire as of late to work with the
open-source community and industry consortiums around
interoperability," wrote Tom Kemp, CEO of Centrify, on his blog.

Centrify, a Microsoft partner, makes software called DirectControl that
lets servers, workstations and devices from other vendors use Active
Directory, which is Microsoft"s authentication and provisioning
technology. Authentication is accomplished using Kerberos, Kemp wrote.

Despite embroiling itself in controversy, Microsoft"s involvement
with Kerberos has also made use of the protocol more widespread, Kemp
wrote.

"As we all know there are many out there that like to beat up
Microsoft regarding security, but it is ironic that Microsoft by
default delivers the added security of Kerberos as part and parcel of
the Windows platform," Kemp wrote.